Optical data communications have recently become quite popular. Prior art optical data communication systems have commonly been based upon infrared (IR) wavelengths and comprise a range of systems from one way links, such as links from calculators to printers, to simple systems to replace the keyboard cable on a personal computer, to high bit rate systems used to construct wireless local areas networks (LANs).
While IR based optical data communications systems have many advantages over radio or cable-based systems, they also suffer from problems not experienced by such systems. Specifically, as most modern IR systems rely upon semiconductor IR emitters and detectors which have a limited IR spectral response, it is becoming increasingly common that IR devices experience conflicts with other IR devices operating at similar IR wavelengths.